Blade grinding machine



Dec. 9, 1941. w. w. HARTMAN BLADE GRINDING MACHINE A '7 Sheets-Sheet lFiled MarCh l5, 1940 inve/2301*: Mllam Walzgr Hari/Ilan.

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'7 sheets-sheet 2 w. W. HARTMAN BLADE GRINDING MACHINE Filed March'l,194c- Dec. y9, 1941.

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William Wall'erllarl'man. @1MM 6MM Dec. 9, 1941. w. w. HARTMAN 2,265,600

BLADE GRINDING MACHINE Filed March 15, 194C 7 Sheets-Sheet 3 /26 WillianWaver Hartman.

DeC- 9, 194. w, w. HARTMAN 2,265,600

BLADE GRINDING MACHINE Filed March 15, 194C 7 sheets-sheet 4 Dec. 9,1941. w. w. HARTMAN l BLADE GRINDING MACHINE Filed March l5, 194C '7Sheets-SheeiI 5 fnv'enl'or. [2y Z: William Wall'erharman.

Dec. 9, 1941. w w HARTMAN I 2,265,600 f BLADE GRINDING MACHINE FiledMarch l5, 194C 7 Sheets-Sheet 6 z en for. Willi am Wqlerarman.

De 9, 1941 W. w. HARTMAN BLADE GRINDING MACHINE Filed March 15, 194C 7Sheets-Sheet '7 fig/1 /l/l der Patented Dec. 9, 1941 UNITED STATESPATENT OFFICE 2,265,600 BLADE @BINDING MACHINE William Walter Hartman,Los Angeles, Calif.

Application March 15, 1940, Serial No. 324,125

anism for `a blade grinding machine of the type 24 Claims.

This invention relates generally to blade grinding machines, and moreparticularly to machines for grinding a scalloped, beveled cutting edgeon a blade. The invention contemplates primarily the grinding of such acutting edge on blades of the iiexible, endless band type, such as arecommonly employed in modern bread slicing Inachines, though not beingnecessarily limited thereto.

A machine for grinding a scalloped, beveled edge on a blade is disclosedand broadly claimed in my prior Patent No. 2,118,197. The blade indexingmeans employed in the machine disclosed in my said prior patent,however, is designed for the relatively short reciprocating type ofblade, and is not designed for a blade of the flexible. endless bandtype, even though the grinding means disclosed is as well adapted forone type of blade as the other. To produce a blade of the scalloped edgetype, a length or band of steel rst has a scalloped shape formed alongone of its edges, which is done by a punching operation, as is wellunderstood. Using a grinding means ofthe type disclosed in my said priorpatent, the blade is then formed with the desired beveled, scallopedcutting edge by moving end holes of a reciprocating type blade, foraccurately indexing the blade, or in other words, for intermittentlyadvancing the blade between positions in which its scallops areaccurately in position for proper grinding action by the grinding wheel.As previously mentioned, however, no means is disclosed in said priorpatent for indexing a blade .of the flexible endless type, which doesnot have end holes or other means adapted for positive engagement by thefeeding means, but must be advanced by friction drive means.

A general object of the present invention is therefore to providesuitable blade indexing mechanism for a blade grinding machine of thetype designed for blades of the endless band type.

A further object of the invention is to provide an indexing meansadapted for cooperation with a blade grinding means of the typedisclosed and claimed in my aforesaid prior patent.

A still further and more general object of the invention is to providean improved blade grinding machine for blades of the scalloped, beveledtype.

Still another object of the invention is the provision of an improvedblade indexing mechdesigned for grinding blades of the scalloped,beveled type.

In accordance with a preferredand illustrative form of the presentinvention, the blade is intermittently advanced by friction driverollers, which feed the blade on each intermittent operation a distanceequal to the distance between the crests of its scalloped edge. Themachine' is carefully designed so that the distance the blade is fed foreach intermittent yfeeding'operation is as closely as possible equal tothe distance between crests of the scalloped blade. ,Nevertheless,because of the frictional nature of the drive between the blade feedingrollers and the blade, ya certain slight but inevitable slippage orcreepage takes place, and even though the amount of such creepage duringeach advancement of the blade may be insignificant, nevertheless suchvcreepage, unless compensated, accumulates 'until a maximum tolerance isexceeded. It is a feature of the present invention that such cumulativecreepage is compensated by movement of the blade feeding rollers in adirection longitudinally of the blade, such movement being of course-insuch a direction as will move the blade bodily in a direction to cancelthe creep-age which has occurred. Such movement of the blade feedingrollers is under the control of means cooperable with the scalloped edgeof the blade, and designed to detect very slight departures of the bladescallops from predetermined position, which position will of course beunderstood to, be that in which a scallop of the blade registersprecisely with the grinding arc of the grinding means. When any bladecreepage has occurredv such as produces a detectable misregistration oftherscallops of the blade from the predetermined grinding position,operation of the means for bodily moving the blade feeding rollers in adirection longitudinally of the blade is brought about, and the amountof such movement and its direction are such as to compensate the saiddetected misregistration.

Various additional objects, features and ac complishments of theinvention will appear and4 be described in the course of the followingdetailed description of a present illustrative embodiment of theinvention, wherein reference is had to the accompanying drawings, inwhich:

Fig. 1 is a plan view of one embodiment of the invention; Y

Fig. 2 is an enlargement of the main portion of Fig. 1,'

Fig. 2a is a detail section on line 2a--2a of Fig. 2;

Fig. 3 is a section through the blade advancing rollers, being taken online 3-3 of Fig. 2;

Fig. 4 is a section taken as indicated by broken line 4-4 of Fig. 2;

4a-4a of Fig. 4;

Fig. 4b is a section on line lib-4b of Fig. 8;

Fig. isasection. taken on line 5`-5 of. Fig. 2;

Fig. is a sectiontaken on broken line 6-6 ofv Fig. 2;

Fig. 6a is an enlargement of a fragmentary` portion of Fig. 6;

Fig. 7 is a section taken on Fig. 2;

Fig. 8 is a view taken as indicated by line 8 8 ofFigs.1and2;

Fig. 9 is a View similar to a portion of Figa, but showing a modication;

Figay A1,0 is asection online -IO-I of-Fig.;2;

Fig.11 isa section'on'line Il-II of Fig. 2;

Fig. 12 is a View taken as indicatedV by--fline l'Z--IZ `of..1iggx2Fig,l 13 anmenlarged` detailtaken from Fig. 12 :f j v Fig. -14 is asection online v'i4- Ill of Fig.- 13 Figff15 isasection-taken online.I5-I5 of, Fig., 121'.; Fig; 16 isa view., takenf as indicatedby line.

Fig.17f isa viewy similar. to a portion of Fig. 12 but showing v,amodification;

Fi,.,-.191is,I a diagram fof anelectricalf circuit;

Fig.;20 is a/diagramof an electrical modified circuit adapted foruse-with themodified .form of the invention indicated infFig..f9;

Fig. 21 is a circle-.diagramindicating ,the cy-v cleof operations of-the machine;`

Fig.@22 is a kinematic diagram illustrating the ation of thegrindingwheel; .Y

Figs/23: is a side elevation-vota portion of.a

' blade-havingaubeveled, scalloped cutting. edge.

suchas. iscontemplatedwby the machine of the present-invention; Y

Figa'Zi4 isf an -en-largedsectiontaken f on line:

24,-:1-124. of Fig/23; and l Fig- 25 is a diagram ...of an Yelectricalcircuit suitable Efor the modification `of Figs.'` 1'7. and 18.Reference-.is `first directed -to Figs. 23 andl 24 slrioyvingk VVaportion.- of a blade, yof thev type.. for which the grinding ...m achinevoi -the present inhere illustrated,..however, .being ofthe .type diszclosed ,and ,broadly claimed inr my aforesaid priorPatent-.No.--2,1.18,197.. Thus in its broadestas pects,. .the,present.invention. is not .essentially concerned wither limited .to .the nature.of the specic means Vemployed toperform the grinding operation, ,solongas there is .provided some .suitable grinding means adapted to workalong a pre determinedY grinding arc, the scallopsv s. of theblade'being brought successively into registra.

broken. line -l-T of .longitudinal center line C-C thereof.

combination of blade indexing means with blade grinding means of thetype mentioned.

The particular embodiment of my invention here Vchosen for illustrativepurposes has a rectangular, substantially horizontal base or frame plate30, preferably sloping gradually toward a drain outletl hole 3|, whichmay be used for circulation of Wash fluid, and provided with anupstanding marginal flange 32. The blade, here shown as of the endless,flexible band type, is indicatedat 433, and, as illustrated, travelsabove and lengthwise of rectangular base 3l), along the In theparticular form of the invention here shown, blade 33 travels fromleftto right across base 30 as Aviewed in Figs.V 1 and 2, the yblade aftervpassing beyondthe right handend-of base being dou-l bled back andtraveling in a contrary direction to oneside ofvbase 30, being finally,at a point to the-left of the left-hand end of base `3i), doubledforwardly to cross base 30 along the longitudinal center line of thelatter as aforesaid. The stretch of blade 33 to one side of base plate3|). may beY supported by any suitable guide means; I here show/a simpleand convenient expedient for this purpose consisting of a pair ofarms.35 extending from opposite ends of Vbase plate 30, `each provided`at its end with a pair of guide pins 31 between .which the blade isreceived, the edge .of the blade resting -onthe extreme end portionoffsaid arms between the guide pins 31,

ventionfis, designed.-. The blade will be seen to s tion or coincidencewith such, grinding arc. 'In -v more specic aspects, however, theindexing or blade vregistering,mechanism of the presentl in-l vention isdesigned particularly for cooperation and coactonjwith thejtype ofrgrinding means disclosedl in mysaidprior'patent; and certain featuresof invention are presented-in-my novel as will be obvious from Fig. 1.The portion of theblade crossingbase plate 30 Vis guided at a y pointsomewhat in advance of said plate between apair of guideY pins 4D spacedon opposite sides of center line.C-C and set into the cross portion llof a bracket 42 secured to and extending from the left-hand end of baseplate 3B, the lower or rearwardvedge of .the blade resting or riding ontheportion 4l ofbracket 42 yas indicated.

Near the opposite or right-hand end of base plate 39, the blade 33passes between a pressure roller 44 and a friction drive roller d5' ofan indexing mechanism (Figs. 2 and 3), said rollers engaging oppositesides Vof the blade withsufcient pressure that when the roller 45 'isrotated, the blade will be advanced without sub# stantial slippage. Theindexing mechanism` of which .these rollers 44 and 45 form a part willbe described hereinafter. Y

Ther blade is .tensioned back of rollers M and 45, at a point locatedtoward the opposite end of hase` 30, so as to provide a tensioned lengthof bladeto be operated on bythe grinding means presently to bedescribed. A simple and illustrative means for so tensioning the bladeis designated generally by numeral 46 in Figs. 2, 12 and 15, andcomprises a bell crank Hipivotally mount-y ed at 48 on base 3i! andhaving one arm 49 formed with a bifurcated upper end 5i! supportingblade guidevblocks 5| spaced apart to provide a guide slot 52 for theblade. I'heseguide blocks may be pressed into moderate frictionalengagement against opposite side surfaces of the blade as by meansofscrews'53, or any other suitable ex-V pedient. The blocks 5I arepreferably formed of some composition material, such as Celeron, adaptedto exert a moderate frictional drag on the blade, and yet to permitslippage therebetween when the feed rollers are advanced. The other arm54 of this bell crank is acted upon by a spring 55 to oppose pivotalmovement of the bell crank as the blade is dragged forwardly be-v ltween the blocks 5l. In operation', the blade is intermittently lmovedYin theV direction of the ar:

row in Fig. 12, and slides forwardly between the blocks l, but by reasonof the moderate frictional drag of the blocks on the blade the bellcrank is rocked against the pressure of spring 55 to some such aposition as illustrated in Fig. 12. When the blade then ceases itsadvancing movement the bell crank remains in the position of Fig. 12,and, under the actuation of spring 55, functions to tension the bladelength between blocks 5I and feed rollers 44 and 45.

Preferably, both sides of the blades are ground simultaneously, thoughto avoid interference between the two grinding wheels, and to enable useof proper blade backing-up means,individual scallops are not groundsimultaneously on both sides.

Accordingly, I preferably provide two blade grinding units 66 and 6I,one on each side oi the tensioned length of the blade between tensioningmeans 46 and rollers 44 and 45, and these two blade grinding units areoffset from one another longitudinally of the blade so as to operatesimultaneously on two suitably spaced scallops of the blade.

In the particular embodiment of my invention here chosen forillustrative purposes, each of grinding units 60 and 6I is of the typedisclosed in my prior Patent No. 2,118,197. The two units may besubstantial duplicates of one another, and corresponding parts thereofwill accordingly be designated by like reference numerals. Each grindingunit has a comparatively thin grinder or grinding wheel 62, having acurved grinding periphery 63, and this grinding wheel is mounted in aconventional manner on a grinder shaft 65, which in turn is rotatablycarried in shaftsupporting means that in this instance comprise the bodyof electric motor 66. Motor 66 serves to drive the grinder shaft, thoughobviously any other means for driving shaft 55 may be sub-- stituted ifdesired. Mounted on the tubular boss 61 at ea-ch end of the case ofmotor 66 is a rectangular block 68. which has a bore 66 receiving boss61, and is split at and clamped tightly to boss 61 by means of screws1I, all as clearly illustrated in Fig. 6.

Block 68, which is thus rigidly attached to the case of motor 66, iscarried by a pair of links 113, each of which is pivotally connected atto block 68, and is pivotally mounted at 16 on a supporting frame 18.Supporting frame 18 has at the bottom a base portion 19 extendingtransversely of blade 33 and formed with a dove-tailed way 86 slidablymounted on a dove-tail supporting plate 8|, the latter being secured, asby screws 82, to a stationary base 83 cast integrally with frame 36.Frame 18, together with the motor and grinding wheels carried therebythrough links 14, is thus mounted for sliding adjustment movementtransversely of blade 33, and it will be evident that this yadjustmentenables the periphery of grinding wheel 62 to be adjusted with relationto blade 33. This adjustment is accomplished through a lead screw 85 forgrinding unit 66 and a lead screw 86 for grinding unit 6|, both beingmounted for rotation in a bearing block 81 cast integrally with base 30,and being confined against axial travel with relation to block 81 as b-ycollars 81a (see Fig. 2). The two lead screws have screwthreadedengagement with internally screwthreaded tubular bosses 88 castintegrally with supporting frames 18, while the ends of lead screws 85and 86 that project outside bearing 81 are squared, as indicated at 89,for engagement by a suitable Wrench or other operating tool.

It will be evident that the links 14, frame 18 'assure clearing theblade-that and motor 66 form a parallel linkage, of such a nature thatthe grinder shaft and grinding wheel 62 can be swung back and forth withan arcuate motion on the iixed pivot connections 16, and thatin thisswinging motion the grinder shaft 65 will always remain parallel to itsoriginal position, as well as to blade 33. The relationships arediagrammatically illustrated in Fig. 22, in which the two extremepositions of the grinding wheel are illustrated in dotted lines 62a and62b, the grinding arc through which this grinding wheel swings beingindicated at A. In order that Fig. 22 may be more readily understood, itshould be noted that the solid lines illustrate the positions of thevarious parts at the center of the grinding stroke, while the dottedlines illustrate the positions of the parts at the extreme ends of thestroke. It is the motion of the grinding wheel along arc A thatcomprises the grinding stroke, and it will be evident that because ofthe arcuate nature of this stroke, the grinding wheel moves closer tothe blade 33 as the mid-point of the stroke is approached, and recedesfrom the blade as the ends of the stroke are approached, which motionresults in grinding along the scallop of the blade, as fully set forthin my aforesaid prior patent.

As previously noted, the two grinding units 66 and 6I are offset fromone another longitudinally of blade 33, so that one grinding wheel willgrind one scallop of the blade while the other grinds another scallopspaced somewhat from the first. This permits a suitable blade back-upmeans to be provided opposite each grinding wheel. As typicallyillustratedV in Figs. 2 and 6, a bracket 92 mounted on base plate 36opposite the periphery of each grinding wheel supports a block 63engaging the side of the blade opposite the grinding wheel. Bracket 92also preferably affords a shoulder at 94 supporting the lower,unsliarpened edge of the blade, as illustrated in Fig.4 6. The center ofthe grinding Wheel is located somewhat above the scalloped upper edge ofthe blade, in substantially the relationship illustrated in Fig. 6, andin sweep-ing toward and against the scalloped edge of the blade, along agrinding arc such as indicated at A in Fig. 22, the grinding wheel actsto grind a beveled edge along the scallop from one crest to the next. It

` will of course be readily understood that the arc and length of thegriding stroke must be properly related to the distance between crestsof the scalloped blade. The length of the arcuate stroke of the grindingwheel is made such as to is, moving slightly beyondthe crests of thescallop-at each end of the grindingstroke. It is essential that thegrinding wheel clear the blade at at least onel end of the stroke, inorder to permit feeding of the blade between grinding strokes, and it ishighly preferable that the grinding wheel clear the blade at both endsof the stroke, as this is conducive to formation cf the desired sharppoints at the crests. f

Any suitable means for moving the members to secure the describedgrinding stroke may be employed, though that illustrated in Figs. 2 and10 is simple and preferred. A drive shaft |69,

A adapted to be driven by sprocket 561 and a suitable power drivenchain, not illustrated, is journaled in bearing brackets 62 mounted onthe left hand end of frame 36, as viewed in Fig. 2. Mounted on thisdrive shaft are a pair of cams |03, one for each of the grinding units,and rolling along the periphery of each of these cams A|103 is a'follower rollerY |04 rotatably mounted ona block |05 on one lend of apush rod |06. l This push rod |06jis furnished with a slide bearing |01mounted von frame 3,0, and has at its other end a roller |08 bearingVagainst the flat face ofl the aforementioned block 08 rigidly mountedon the tubular boss 61 of the motor case of the grinding unit.

Push rod block |05 is supported from shaft |00 by means of parallelstraps ||0 and a connecting block H011, straps l! 0 slidably engaging ablock rotatably `mounted on shaft |00, in the arrangement clearlyillustrated in Figs. 2 andV 10.l As push rodf|06 is advanced by cam |03,roller |08 in engagement with block 58 of the grinding unit causes thegrinding unit to advance through its arcuate grinding stroke,

roller |08 rolling on the face of Vblock 08 to accommodate the componentof movement of the grinding unit transversely of the push rod. In theparticular embodiment of the invention here Y illustrated, the returnstroke of the grinding unit'is accomplished by vmeans of a tensionspring ||5 connected between block 58 and a suitable bracket mounted onthe flange 32 of frame 30, in the arrangement indicated in Fig. 2, thisspring acting to hold block 68 in engagement with'roller |08 andfollower roller |04 in engagement with the periphery of cam |03 at alltimes, and thus constituting the motivating agent for the returngrinding stroke.

A'preferredform of blade indexing mechanism, of which the previouslymentioned blade engaging rollers 44 and v45 form a part, will now bedescribed. Roller 45 is positioned above and selcured to a vratchetwheel as by means of screws |2|, and roller 45 together with ratchetwheel |20 are rotatably mounted on the shank portion |22 of a screw |23set into a carriage |24. Ratchet wheel |20,'which is intermittentlyadvanced by pawl mechanism later to be dee scribed, is held againstreverse rotation as by means of a one-way clutch |20a of the rollerratchet type placed within the hub of roller 45, and the balls orrollers |2511l of which engage shank |22, as illustratedY in Figs. 3andv 4a. Carriage |24 has a base |26 mounted for sliding movement in adirection parallel to blade 33 on a plate |21 mounted on base v30, forinstance, in the manner clearly illustrated in Fig. 3. Any suitablesliding connection may be provided between base |25and plate |21; in thepresent instance, retainer strips |29 secured to base |25` provide aT-shaped slot in which plate |21 is slidably received.

Blade 33 is received between the rollers 44 and 45 in the manner clearlyillustrated in Fig. 3, and in the present instance, roller 44 isadjustable toward and from roller 45 in order to adjust the frictionalengagement between the rollers andthe blade. Thus, in the embodiment ofthe invention here shown, roller 44 is mounted for rotation on theenlarged shank portion |35 of a screw |36, said screw |36 having areduced and screwthreadedA shank portion |31 extending downwardlythrough an adjustment block |38, the` shoulder between shank portions|35 and |31 of screw |35 engaging the upper surface of block |35 and anut |39 screwthreadedon the lower end of screw |35 being set up againstkthe lower side of said block |38. A bearing sleeve |40 is placed betweenshank portion |35 of screwv |36.and roller 44, and a washer |4| spacesroller 44 from the upper side of block |38. Opposite' sides ofblock'|38. aremformedwith grooves or ways |42, whichslidably receivel guiderails |43 secured to parallel ribs or. flanges |44 formed on carriage|24. Block |38 yand roller 44 carried thereby are thus adjustable oncarriage |24 in a direction toward and from blade 33.

A thumb screw |46screwthreaded through a strap |41 secured to the endsof rails |43 engages block |38 and adjusts the position of the latteralong rails |43. Thus,.theblade 33 being in posi-- tion between rollers44 and 45, the pressural engagement of the rollers on the blade may beadjusted by setting up the mounting block |38 for roller 44 by means ofscrew |40. Adjustment of the pressural engagement of the rollers on theblade is made suicientthat the blade may be advanced without substantialslippage when'roller 45 is rotated, while at the same time the pressuralengagement is not made so great as will cause undue tightness or bindingof the parts.

Roller 45 is intermittently advanced by means of an intermittent pawlmechanism cooperating with the aforementioned ratchet wheel |20. VA ilatlever 50 is rotatably mounted on sleeve |50a between ratchet wheel |20and the upper end of carriage portion |24ar (Figs. 2, 3 and 4) 'and thislever |50 has pivotally mounted-thereon va pawl |5| adapted forengagement withv the teethof ratchet wheel |20, in the relationshipillustrated in Fig. 2, pawl |5| being furnished with a usual spring |52holding it against ratchet wheel |20. Ratchet wheel |20 isintermittently advanced by pawl |5| through intermittent pivotalmovement of lever |50 on the aXis of the ratchet wheel, as will beunderstood. Such movement of lever |50 is, in the present instance,produced by means of a reciprocating push rod |55 mounted in a slidebearing |56 securedv toV base 30 and engaging the edge of lever |50 (seeFig. 2a). Push rod |55 is operated by arm |51 of a bell crank |58pivotally mounted on base 30 at |59, the other arm |50 of said bellcrank being operated by connecting rod |6| by means presently to bedescribed. Tension spring |52 suitably anchored to the frame andconnected to the swinging end of lever |50 retracts the latter, togetherwithrpawl |5|, at the end of the advancing or feeding stroke thereof,while the roller ratchet clutch seen'in Fig. 4a supports the ratchetwheel against reverse or return rotation.

The rearward end of connecting rod |!|v isV pivotally connected at |65to a push rod |66 working in a slide bearing |61 mounted on base 30. Onthe rearward end of push rod |66 is a block |58 which carries a camfollower roller |63 which is engaged by the periphery of a cam |10mounted on drive shaft |00. Push rod block |58 is indicated as supportedfromshaft |00 by means of parallel straps |1| and a connecting block|12., straps |1| slidably engaging opposite sides of a block |14rotatably mounted on shaft |00, as will be understood from inspection ofthe drawings. c

Cam |10 is so designed that at theproper time, as will later bedescribed, push rod |36 and connecting rod IBI are advanced, therebyswinging bell crank |58 in a right-handed direction, as viewed in Fig.2, to move push rod 55 against lever |50 and thereby swing the latter onthe axis of ratchet wheel |20, this movement resulting in pawl |5|carried by lever |50 advancing ratchet wheel |20 one step ahead. Bladeengaging roller 45 vis thus rotated through a limited distance, andfeeds blade 33 a corresponding distance ahead. The design of'this bladefeeding or advancing mechanism is of Course such as will feed the bladea distance equal as precisely as possible to the distance between thecrests of its scalloped edge. The spring |62 connected to apawl-carrying lever |50 serves to return the linkage at the conclusionof the advance stroke,

acting at all times to maintain follower roller |69 against theperiphery of cam |10.

Reference is now directed to Fig. 21, which is a circle diagram showingthe sequence of operations of the machine and the synchronous relationsof its several component units or mechanism. The outside circle, ABCDEF,represents a complete cycle of operations of the two grinding units 60and 6| as operated by cams |03, the dotted line position OX representingthe position illustrated in the drawings, which is at the mid point ofthe advancing grinding stroke, that is, in the direction away from thecams |03, as indicated by the arrows placed alongside the grinder motorsin Fig. 2. The grinder units are at the beginning of the advancingstroke at position F in Fig. 21, and are advancing to bring theirrespective grinding wheels into grinding engagement with the crests ofthe scallops about to be ground from F to A in said figure. From A to Bthe grinding wheels are in engagement with the blade and sweep fromcrest to crest of the scallops being ground. From B to C the grindingwheels move beyond cr clear the crests of the scallops; at C, thegrinder units reverse direction; and at D the grinder wheels againengage the blade, sweeping from crest to crest along the scallops in thereverse orreturn direction between positions D and E. At E the grindingwheels clear the crests of the blades, and from E tc F return to thestarting position. The cams |03 are preferably so shaped that the majorproportion of the cycle is devoted to the grinding operation occurringfrom A to B, since this is the first or rough cut, and should beperformed relatively slowly. The grinding wheels are clear of the bladefor only a very short interval from B to C, and the return or finishcut, from D to E, is performed with substantially increased speed, aswill be apparent from Fig. 21. The grinding wheels are clear of theblade following completion of the finish cut for a period represented byEA, which period is of suicient duration to permit the indexingmechanism to advance the blade while the grinder wheels are clear. Thisis indicated by the second circle, GHI, the indexing mechanism operatingto advance the blade between a point G corresponding with point E (thepoint of termination of the finish cut) and a point I-I which is aheadof the point at which the grinding Wheels again engage the blade. Theindexing mechanism then returns or retracts, with the blade remainingstationary, from H to I. The cam |18 operating the indexing mechanism isof course so shaped and so mounted on shaft relatively to cams |03 as togive these relations, suitable cam shapes and relative angular positionsfor this purpose being illustrated in Figs. and 11.

Now while the describ-ed indexing mechanism is carefully designed andadjusted to advance the blade on each actuation a distance preciselyequal to the distance between crests of the scalloped blade,nevertheless, owing to the fricticnal nature of the drive between theblade feeding rollers and the blade, a certain inevitable slippage orcreepage takes place, and even though the amount of such creepage duringeach advancement of the blade is of no particular moment, or not evendetectible by ordinary observation, nevertheless the creepage thataccumulates for several feet of travel of the blade may amount toseveral thousandths of an inch,

Awhich is greater than a maximum tolerance.

The present invention compensates for such cumulative creepage by theprovision of means Cooperable with the scallops of the blade anddesigned to detect any displacement of the scallops from their properpredetermined position with relation to the grinding means for propergrinding action by the latter with the particular scallop then inregister therewith, in combination with means for eifecting relativemovement between the blade and grinding means to compensate anydisplacement that may thus be detected. In a preferred form of theinention this relative compensating movement between blade and grindingmeans is accomplished by a suitable movement of the blade engagingrollers 44 and 45 by or between which the blade is held, and while it iswithin the broad scope of my invention to move said rollers in anyfashion or manner to secure a longitudinal compensating movement of theblade, there is here illustrated a preferred form of the invention inwhich such movement of the blade is secured by a movement of thecarriage |26 on which the blade engaging rollers 44 and 45 are mountedin a direction longitudinally of the blade, in such manner that saidrollers bodily move in a corresponding direction, and hence move theblade along with them aswill now be described in detail.

A lead screw I journaled in a bearing |8| formed at the end of base 30opposite carriage |24 has screwthreaded engagement with the carriage at|82, lead screw |80 being confined against longitudinal movement withreference to bearing |8| by means of a flange |83 and a collar |84.Tightly mounted on the extremity of lead screw |89, forwardly or outsideof flange |83, are a pair of ratchet wheels and |86, having oppositelydirected teeth |85a and |86a, respectively. Cooperable with ratchetwheels |85 and |86 is suitable pawl mechanism adapted to effect rotationof lead screw |80, and therefore longitudinal travel of carriage |24, ineither direction. One simple example of such pawl mechanism isillustrated in the drawings, and embodies a beam |90 pivotally mountedat the center on the end of lead screw |80, forwardly of ratchet wheels|85 and |86, and a pair of pawls |90 and |9| pivotally mounted on thetwo arms of beam |90 in positions for operative engagement with ratchetwheels |85 and |86, respectively. These pawls are held normally out ofengagement with the ratchet wheels by means of tension springs |92, andthey are actuated to engage and advance the ratchet wheels by means oflinks |93 connecting them with the plungers |94 of solenoids |95, thelatter being mounted on a supporting bracket |96 secured to the end ofbase frame 30, all as clearly illustrated in Figs. 2, 4 and 8. Tensionsprings |91 connected between opposite ends of beam |90 and bracket |96yieldingly hold beam |90 in a horizontal position, with solenoidplungers |94 supported in elevated position by means of springs |92.Energization of either of solenoids |95 causes the correspondingsolenoid plunger 94 to be moved in a downward direction, link |93thereupon acting against spring |92 to move pawl |9| into engagementwith the corresponding ratchet wheel, after which further downwardmovement of plunger 94 and link |93 causes beam |90 to swing downwardlyand thereby advance the ratchet wheel,

6 'This results in a certain rotation of lead screw I 80 and a smalllongitudinal adjustment "of carriage |24, and therefore of blade 3 3,the 4blade en'- gaging rollers 44' and 4 5 mounted on' carriage |24moving the Vportion of the' bladeclamped between! them either forwardly-or rearwardly' as Y1,h`ecase may be. If*4 the adjustment movementisi-in a direction to move the blade in a forward direction, the blademay either slide forwardly 'a corresponding distance betweenthe bladet'ensioning blocks lll at-the other end of thev tensioningsection of theblade, or if such'slippa'ge does not-occur, bell crank may tilt:slightly -forwardl-y against spring 55. lIf the adjustment movement is:in the reverse directiomthebell crank d6 movesunder the actuationofspring 55 toVVV take up the slackV and maintain the blade tension. f Anyplayin the adjustment means due tobaoklash'in the screwthreads at`|8`2is taken care of owingto theV tensioning-"of the blade by tensioningmeans ,46; To supplement thisaction, lImay place aL compression-spring|9`|a around lead screw |83 between collar |84 and carriage |24, thisspring actin'gfieiectively to removea'ny undesirable play between thevlead screw vand carriage |24; i Y Y lMeans Yare providedcooperablerwith the scallops-of the bladefor energizingv on'eor theother ofthe two solenoids |95to 'cause--z`a, d justment fin theVlongitudinal position of the blade relative 'to the grindingwheelswhenever the scallops of the blade creep appreciably from a position ofvregistration with the grinding arcs ofthe grinding wheels. As fone`typical embodiment of `'such means, I show inthe vdrawings a mechanicalfeelermember 26) cooperable with; successive Y crests ofl the-"scallopedblade, being in this case in the nature of a saddle which engages andrides ther `bladeedge on :opposite Vsides-of successive crests, anddetects any'departure of acrest of the blade from its predeterminedproperT position with relation to theV grinding arcs invention,

'^ YIn vthe present embodiment-oi the the/saddle' elementl'is -in theferm of a disk 29| havingfaboregZZ of smallerV diameter sunk inthe frontface thereof, the-circles 4of the bore 22 and ofl diskj28| being tangentat the bottom, andthe-stock of the diskbeing cut away'at the bottom 'toform tw'olhorns or feelerelemenfts 283,

allias will readily beunderstood froman ins-pection 'o'f Figs. 13 and14".' These--feeler elements N3 are adapted to be let down andtoengagethe edge of l'the blade on -opposite/sides of itsforestas inFig. 13, preferably being rounded over somewhat 'so asV to avoid anyliability of nicking` the edge of the blade.v Saddle 200 istightly/'mounted Y on oneend of Vastud-2|l5I which is Vpivotally mountedin the swinging end of the arm26` of Va beam 201,' the latter beingpivotally supported at 22B-on suitable supporting means 269 mounted onframe 35; As will be seen in Fig. 12,' saddle 2e!) Vengages blade 33between the grindingV units `and bladejtensioning means 46, andtherefore engages the blade prior to operation `'ofv the ,grindingmeansthereon, though 'witlxin the' tensioned length of'theblade. Theother arm 12|!) of beam 29T carries A`a roller 2 which Yisintermittently engaged by la cam 2`! 2 ,mounted ond'rive 'shaft |90.vArm 2&6 Vis' shown as counter-weighted, as air-286i, sonas tojallowsaddle AZilatorest on blader At such time, the roller'2 I I'is outof engagement.,V Cam 2-|2 is designed to engage roller 2 Yt'o liftarmf-an'd thereby disengage saddle 2GB-'from the-'blade while'theindexing meenanism" is in operation, 'fand "'tltienVV immediately; to

aeeaeob `allow arm .2% to lower to lbring saddle 200 back Aintoengagement With-th neXt-Crst' 0 f tlbld. A springZ i3 mayprefeablybe-employed' to vyieldingly oppose movement of the Ibeam by thecam', and to vassurel prompt return ofthe beam/tela position in Whio'hthe saddle'v engages the blade. The timing is indicated-by 'the'diagram`- ofFig. 2l, the saddle being lifted 'between' points G 'and H,in a A*manner toA clear theblade beforeI theindeXi-ng 'mechanism'operates,A and moving' down 'between' points H and I, inf a vmannersuch' that the blade is not engaged until theV index-ing mech'- anisnihas'completed' the blade feeding operation.

Ri-gidly mounted on 7 saddle stud Efontle opposite'side of arm 296lf-rornsaid saddle, is"a depending arn-i 2| tithat has'lat its lowerendtwo oppositel'y facing electrical contacts 216 and 2H'. These contactsZib'and 2H are y'adapted tomak'e With/.Contacts ZIS and2|9,freSpe'ctvely,i` `asarl 2 l5 swings to one side or theotherof itsnormal 'vertical p`osition.- Arnd` 2|?, pivotally connected 'withand'suspendedfrom' the arm- 296 of beam '2M normally positionssaddleZwith its two feeler elements ilin a precisely levelrelationship.r Ifwhenthesaddle i'sflowered into engageinent'witl'l thebladeas'vaforesai'd, ythe* crestor the blade is accurately alinedwiththe loeni'le'r of "the Saddle, or in other w'ores, with the axis' ofsaddle 'stud' '2535 (under which lcor1 litions two scallopsof tle'bladewill 'coincide accurately with the grind"- -in`g aros A of the two-gr'indingfunitslfeeler'elev4ments '203 'Willengage th'e edge-ofv thebla'deon 4opposite `sides of `the crest "sirnulta-neously,I and thesaddle will not be rocked to oneside or the otherso thatarm 2 i5 hangsvertically, "withboth contacts 2id and 2H spaced from theirrespectivefrnating contacts 2&3 f and 3219. HIf, `on the othery hand,the -crest ofV theblade lshould Abe displacedslightly to one side'oftheaxisiof'saddle 2&9, then one'or the other of feeler elements 203 willengage the blade Arlrst,'thereby causing Vthe saddle tofrock slightlylon the laxis offstud 205. This results in swinging of varm I2| 5 to'one `side of vertical,l so as to'cause contaetto be made beltween'contacts 2H 'and 2|9, or-2 itA and-g2|'8, rdepending upon the4direction ofl swingof arm. 2|' 5, and therefore uponl the direction" inwhich A'the Vcrest of *the blade Vis offset from'the pivotal axisgrindings Yentering within' contactv 'housing' 221].

" Fig, A19 shows diagrammatically a typical electrical circuit wherebyarm 42|j5 controls en'ergiz'ation ofi-the previously'deseribediisolenoidsl |95. Lead 22| connected t0 Contact 2|@ goes to arelay winding 23E, the circuit vcontinuing v iatlead 23| 253! aregrounded tothe frame `oi'th'e machine,

as'indicated Fig. 19.` Leadlsimilarly connects to' relay winding 233,the'circuit continuing via lead 234:and battery 232 to ground. Relaywindings i233A and 233 controlV operation'of' relay armature 235, thelatter being adapted to Connect either of contacts se :0r-2.31 co-groundasv/ mai ing 233 or 23B, respectively,isY energized. One'of solenoids isconnected by V-a'le'ad '238' to contact' 236, While `rtheotlierof:solenoids |95' is connected by a lead 239to contact 231. A suitablesource of electrical current 24B, 24| is connected to the other side ofeach of the two solenoids |95, and to ground, as diagrammed.

It'may now be understood that whenever the crest of the blade engaged bysaddle 20|! is displaced in one direction or the other from the pivotaxis of the saddle, which will mean a corresponding displacement of theblade scallops then to be ground with reference to the grinding arcs ofthe grinding units, the engagement of the saddle with the blade willcause the saddle to be rocked to one side or the other, depending uponwhich of the two feeler elements 293 of the saddle first engages theblade. This causes the depending arm 2|5 connected with the saddle andsuspended from arm 206 to swing to one side or the other, as the casemay be. Because of the considerable length of the arm 2|5, even a veryslight displacement of the crest will in this way cause contact to bemade between either contacts 2|6 and 2|8, or contacts 2|'I and 2|9,depending upon the direction of swing. This lresults in closing acircuit energizing either relay winding 230 or relay winding 233, whichin turn closes a circuit through one or the other of the two solenoids|95. As previously described, energization of a solenoid |95 causesoperation of pawl and ratchet mechanism to rotate lead screw |89 througha few degrees of angular rotation, thereby causing translation of indexmechanism carriage |24 and hence longitudinal adjustment ofthe bladeposition. Connections are of course so made that this longitudinaladjustment of the blade is in a proper direction to correct thedisplacement of the blade crest from the pivot axis of saddle 200 whichwas responsible for closure of the circuits performing or controllingthe described longitudinal blade adjustment. r'ihe amount of creepage ofthe blade, or in other words the amount of displacement of a bladecrest' from the pivotal axis of saddle 20B, which enters for eachactuation of the indexing mechanism is very slight, and may be only asmall fraction of a thousandth of an inch. Depending upon the accuracyof operation of the indexing mechanism, several actuations of the lattermay take place before suiiicient creepage of the blade has accumulatedto result in suliicient swing of arm 2 |5 to set the compensatingmechanism into operation. Once arm 2|5 has swung sufliciently to causecontact to be made at 2|6, 2|8 or 2H, 2 |9, however, the ratchetmechanism will be operated to adjust the longitudinal position of thebladevin such a direction as to compensate the blade creepage which hasoccurred. One operation of the ratchet mechanism may be sufficient tomove the blade a distance such as will cause the arm 2 |5 to open theelectrical circuit causing energization of theratchet solenoids, or itmay be that several such operations, taking place as the saddle engagesthe blade at successive crests, may be required to accomplish thenecessary longitudinal adjustment of the blade, this of course dependingupon the creepage permitted by the indexing mechanism, upon the angularrotation of lead screw |80 for each actuation of the ratchet mechanism,and upon the pitch of lead screw |35. The compensating mechanism issufficiently sensitive that the inevitable more or less constant bladecreepage is never permitted to accumulate to a sufcient extent tointerfere with proper grinding of the scallops, being compensated bytranslation of the indexing rollers and blade before the displacementexceeds an allowable tolerance.

Figs. 9 and 20 show a modication, in which a reversible electric drivemotor is substituted for the pawl and ratchet mechanism of thebladecreepage compensating means, Fig. 9 being a view similar to aportion of Fig. 4 but showing the substitution of the electrical drivemotor, and Fig. 20 being a typical wiring circuit suitable for use withsuch motor.

In Fig. 9, the lead screw lla has mounted thereon a worm wheel 300driven by a worm 30| on the shaft 302 of a reversible electric drivemotor 303 mounted on the frame 39 of the machine, which may otherwise bethe same as the embodiment previously described.

In Fig. 20, which shows the wiring circuit for the modication of Fig. 9,the grounded saddlecarrying arm is again indicated at 2|5, and thecircuits closed by said arm are again indicated by numerals 22|, 23| and22,2, 234, said circuits including source of current 232, which isgrounded as indicated. These portions of the circuit are the same as inFig. 19. In place of the solenoids of Fig, 19, however, circuits 22|,23| and 222, 234 are diagrammatically indicated as including Opposedsolenoids 3||l and 3| respectively, within which work a movable corememb'er 3|2. The motor 393 is indicated in Fig. 20 as being of a shunttype, with a reversible shunt field 3M, the motor being supplied withelectrical current from a suitable source 3|5, 3|6. Shunt winding 3|4 isconnected to two stationary electrical contacts 3| and 3|3, whilemovable core member 3|2 carries three electrical contacts 3|9, 320 and32|. Of the latter, the two outside contacts 3|9 and 32| are connectedtogether, and are also connected to one side 3|5 of the source ofcurrent. Middle contact 329 is connected to the other side 3|5 of thesource of current. With solenoid 3|| energized, which occurs when saddlearm 2|5 closes circuit 22|, 23|, core member 3| 2 moves to bringcontacts 3|9 and 329 into contact with contacts 3|8 and 3|'|,respectively, thus connecting winding 3|4 in shunt with the armature ofmotor 333 and causing motor 303 to run in one direction. When solenoid3|() is then subsequently energized, upon saddle arm 2|5 closing circuit222, 2315, core member 3|2 moves to bring contacts 32! and 32| intocontact with contacts 3|!! and 3|'|, respectively, thereby connectingwinding 3M in a reverse sense across current supply source 3|5, 3|G. Themotor then drives inthe reverse direction. Electric motor 303 thus runsin one direction or the other, depending upon arm 2|5 being swung to oneside or the other as the crest of the scallop straddled by the saddleelement 200 becomes displaced in one direction or the other from theaxis of the saddle. Such operation of the motor rotates lead screw |8|lathrough gears 39| and 323, thereby eifecting a compensating adjustmentof the blade as before. It will be evident that motor 333 will run untilthe crest of the blade straddled by the saddle element has been movedtoward vertical aline- -ment with the axis of the saddle elementsufficiently to break the circuit being held closed by the arm 2|5..

Figs. 1'7, 18 and 25 illustrate a further modification, in accordancewith which the saddle operated arm, in this instance designated bynumeral 2|5a, control-s the illumination of a pair of photo-electriccells, which in turn initiate operation of the mechanism which adjuststhe longitudinal position of the blade. Thus, arm

2 Ilia has on its lower end a shutter element dal),

which controls the illumination of afpair ofA photo-electric cells 34|and 342'by aY pairofil- Y luminants '3523 and 344, respectively. Thearrangement is made such that when arm 2'55 is hanging inverticalposition, With the crest of the blade straddled `by the saddle inY closevertical alinement with the saddle airis'the shutter'el'ement 340intercepts all light travelling toward the photo-electric cells, fromboth illuminants $133 andV 3M, but when arm 2rl5a swings in VonedirectionA or the other, as the crest of the blade becomes displaced inone direction or the other, lightfromI one or the otherilluminantsisallowed to reach its corresponding photo-electric cell. In thespecific embodiment here illustratedj'this is accomplished by providingshutter element 346 with a plurality of vertical lightpassingaperf turesor slotsli, and by 'providing an aperture plate 31H Vhaving aYcorrespending plurality vof light apertures or slot-s 3dS. Theilluminants 343 and 3M andthe photo-cells 3M and 3&2 are Separated bylight shields 349. The set of light apertures y3445 on one side of saidV'shieldsa're vso placed that a very small movementof shutter Silit?Y inl onel direction brings the corresponding shutter v`apertures 3dS intoregister with said apertures 348, While the set of apertures Stdon theother side of light shields 349 areso placed that a very small movementof shutter element 349 in the `opposite direction brings thecorresponding shutter apertures 3% into register with the last mentionedset'of apertures 368. Shutter 346 is limited in movement in eachdirection to an amount of travel which will accomplish the'describedregistration of apertures on one side ho1" the light shields35S without causing registry tof the light apertures on the other sideof said shields by means of stops 359, as will be understood. Thus, inthe arrangement detailed in Figs 17 and 18, movement of arm ZIM-andshutter 3ds toward the right will cause registration of the laperti'lresSd and 35,8 on Ythe left-hand side of shields 35%, and thereforeillumination of photo-,ceu se: byiuuminant 34s. Movement of arm la andshutter 35i) toward the left, on the other hand, effects registration ofthe apertures 3dB and 3dS on the right-hand side oi shields 3119, andtherefore illumination of photc-cell' by illuminant 34s,

Illumination of photo-cells 34H or 342 in the manner Adescribed Vin thepreceding paragraph causes operation of the compensating mechanismthrough an Velectrical circuit, one example of which is diag'r-ammed inFig. 25, which will be seen to be the same as Fig. 9, except for themeans employed for energizing relay Ywindings `23!) and 233.' It will beunderstood that' any suitablel means will be provided whereby relaywinding 23E] Y is energized when light impinges on Vphoto-cell gril, andwhereby relay Winding'233 is energized when light impinges on photo-cell342. Thus, as a typical example, the outputs of photo-cells 341 and 3&2may be conducted to conventional vacuum tube amplifiers,diagrammatically indicated at 360 and 36E, respectively, the outputsfrom which are connected, respectively Vto relay Windings 231! and 233,and it will be understood that Y the output of either of saidphoto-cells'resulting from vlight impingement thereon will cause ritscorresponding amplifier to deliver suicient current to eiect operationof the corresponding relay; vOperation of either of relays 230 and 233eifects energization o f the corresponding ratchet operating solenoid195, thereby effecting compensating adjustment ofl th'e blade in theman-ner detailedV in connection with the rst described form of theinvention.

It Will be understood that the several forms of the invention hereindescribed-and illustrated are merely illustrative of .and notrestrictive on the many forms which my invention may assume in practice,and it it thereforetobe. understood that numerous changes in design,structure andarrangement may be made. without departing from the spiritand scope ofthe invention or of the appended claims.

I claim: Y f

1. In a machine forr grinding a scalloped, beveled cutting edge on kablade, the combination of a frame, frictionalV blade feedingmeanssupport-- ed by saidframe and adapted for frictional drivingengagement with the blade, means on'said frame for intermittentlyoperating said blade feeding means to advance the blade throughadistance equal substantially to the distance-'between crests of thescalloped blade, a grinding means mounted on said frame and`^operable togrind a scallop Vof the blade Whenxthe blade ispositioned withitsiscallops a lpredetern'lined longitudinal position with relation tosaid grinding means, blade creepage compensating means forinoving thebladeY ina longitudinal direction, and means cooperable with-thescallops Vof fthe blade for controlling operation of said compensatingmeans.

,2.111 a machine for grinding a scalloped, bev.- eled cutting edgeon ablade, the combination of f a frame, frictional blade feeding meanssupportedk by said frame and adaptedrfor fritional driving engagementwith the blade, means onsaid frame for intermittently operating saidblade feeding means to advance the blade through a distance equalsubstantially tothe distance between crests of the scalloped blade, vagrinding means mounted on said frame and oper-able to grind a scallop ofthe blade when the blade is positioned with its scallops in apredetermined longitudinal position with relation to said grindingmeans, blade creepage kcompensating means formoving said blade feedingmeans vwith relation to s-aid frame in amanner to adjust the positionvofthe .blade in a longitudinal direction, and means cooperable withth'e scallops of the iblade for controlling opV eration of saidYcompensating means,

3. In a machinefor grinding a scalloped, beveie'd cutting edge 4onablade, the combination of' a frame, frictional blade feeding means`support.- ed-by said frame .and adapted yfor frictional Vdrivmeansmounted on said frame and operable to grind a scallop of the blade whenthe blade is positioned with its scallops in a predeterminedjlongitudinal position with relation to said grinding means, bladecreepage compensating ineansfY for effecting relative movement inradirection ,y

longitudinally of the blade between said frictional blade 'feeding meansand said grinding means,Y Y and means cooperable with th'e scallops ofthe bladefor controlling operation of said compensating'means. Y

4. In a machine for grinding a scalloped, beveled cutting edge on ablade, the combination oa frame, frictional blade eeding meanssupportedV by said frame and adapted for frictional drivingV engagementwith the blade, means on said frame.

for intermittentlyl operating said blade feeding means to advance theyblade through a distance equal substantially to the distance betweencrests of the scalloped blade, tensioning means frictionally engageablewith the blade for tensioning a length of the blade between saidtensioning means and thesaid blade feeding means, a grinding meansmounted on said frame and operable togrind a scallop of the blade withinsaid tensioned length' of the blade when the blade is positioned withitsv scallops in a predetermined 1ongitudinal position with relation tosaid grinding means, blade creepage compensating means for effectingrelative movement along a direction line longitudinally of the bladebetween said blade feeding means and said grinding means, in a manner toadjust ther longitudinal position of the blade with relation to saidgrinding means, and means cooperable with the scallops of th'e blade forcontrolling operation of said compensating means.

5. In a. machine for grinding a scalloped, beveled cutting edge on ablade, Athe combination of a frame, frictional blade feeding meanssupported by said frame andy adapted for frictional vdriving engagementwith the blade, means on said frame for intermittently operating saidblade feeding means to advance the blade through a distance equalsubstantially to the distance between crests of the scalloped blade,tensioning means frictionally engageable with the blade for tensioninga. length of the blade between said tensioning means and the said bladefeeding means, a grinding means mounted on said frame and operable togrind a scallop of theblade withsaid grinding means, and meansycooperable with the scallops of the blade` for detecting displacement ofthe scallops from said predetermined position withV relation to saidgrinding means and to effect operation of said compensating means tomove the blade in a direction to` correct such detected displacement. 1

6. In a machine for grinding a scalloped, beveled cutting edge on ablade, the combination of a frame, frictional blade feeding meanssupported by said frame and adapted for frictiona-l driving engagementwith the blade meansl on said frame for intermittently operating saidblade feeding means to advance the blade through a distance equalsubstantially to the distance between crests of the scalloped blade,tensioning means frictionally engageable with the 'blade for tensioninga length of the blade between said tensioning means andthe said bladefeeding means, a grinding means mounted on said frame and operabletogrind a scallop of the blade within said tensioned length of the bladewhen. the blade ispositioned with its scallops in a predeterminedlongitudinal position with relation to said grinding means, bladecreepage compensating means for moving said blade feeding means inreverse directions in a manner to movethe blade longitudinally in eitherdirection with relation to said grinding means, a feeler memberengageable with the blade edge on opposite sides of successive crestsbetween scallops for detecting displacement of the scallops from saidpredetermined position With relation tosaid grinding means, and meanscontrolled by said feeler member for' 'ei'ectingoperation of saidcompensating 'means to-mov'e the blade in a direction to correct suchdetected displacement.

7. In a machine for grinding a scalloped, beveled cutting edge on ablade, the combination of a frame, frictional blade feeding meanssupported b-y said frame and adapted for frictional drivingengagement'with the blade, means on 'said frame for lintermittentlyoperating said blade feeding means' tol advance the blade through adistance equal substantially to the distance between crests of thescalloped blade, tensioning means frictonally engageable `with the bladefor tensioning a length of the blade between said tensioning means andthe said blade feeding means, a grinding means-mounted on saidf'rame andoperable to grind aA scallop of the blade within said tensioned lengthof the blade when the blade is positioned with its scallops in apredetermined longitudinal position with relation to said grindingmeans, lblade creepage compensating means for bodily moving said bladefeeding means relatively lto saidl frame in a direction longitudinallyof saidtensioned length of blade ina manner to adjust thelongitudinalposition ofthe blade with relation to said grinding means, and meanscooperable with the scallops of the blade for controlling operation ofsaid compensating means.

8. In a machine for grinding' a scalloped, beveled cutting edge on ablade, the combination of a frame, a blade feeding roller adaptedforfrictional driving engagement with the blade to be ground, means forsupporting the blade in 'frictional driving contact with said roller,means for tensioning a length of the blade adjacent to 4said feedingroller, roller supporting means on said frame supporting said roller forrotation on its axis and for bodily movement with'relation to said framein a ydirection longitudinally ofthe blade, means for intermittentlyrotating said feeding roller through an angle such as will feed theblade ahead a distance substantially equal to the distance between bladecrests, a grinding means mounted on said. frame and operable to grind ascallop of the tensioned length of the blade when the bladeis'positioned with its scallops in a predetermined longitudinal positionwith relation to saidgrinding means, blade creepage compensating meansfor bodily movingsaid roller in directions longitudinally of the bladein a manner to adjust the longitudinal position of the blade withrelation to said grinding' means, and means cooperable with the scallopsof the blade for controlling operation of said compensating means.

9. In a machine for grinding a scalloped, beveled cutting edge on ablade, the combination of a frame, a blade feeding roller 'adapted forfrictional driving engagement with the blade to be ground, a roller forsupporting the blade in frictionaldriving contact with said feedingroller, means for tensioning a length of the blade adjacent to saidfeeding roller, a carriage for said rollers mounted on said frame formovement longitudinally of the blade, said rollers being rotatable ontheir axes on said carriage, means for intermittently rotating saidfeeding roller through an angle such as will feed the blade ahead adistance substantially equal to the distance between blade crests, agrinding means mounted on said frame and operable to grind a scallop ofthe tensioned length of the blade when the blade is positioned with itsscallops in apredetermined longitudinal position with relation to saidgrinding'means, blade creepage compensating means including means formoving said roller carriage on Asaid frame ina direction longitudinallyof the blade, and means cooperable with the-scallops of the Vblade forcontrolling movement of said roller carriage.

l 1Y0. In a machine for grinding a scalloped, beveledv cutting edge on ablade, the combinationV of va frame, a blade feeding roller adapted forfrictionaljdriving engagement with the blade to be ground, aroller forsupporting the blade in frictional driving contact with said feedingroller, means for tensioning a length of the blade adjacent to saidfeeding roller, a carriage for said roller mounted on said frame formovement longitudinallyof the blade, said rollers being rotatable ontheir axesV on said carriage, means forintermittently rotating saidfeeding roller through an angleV such as will feed the blade ahead'adistance substantially equal to the dis- .tance between blade crests, agrinding means mounted on said frame and operable togrind a lscallop ofthe tensioned length of the blade -when the blade is positioned with itsscallops in Aa predetermined longitudinal position with relaa tion tosaid grinding means, blade creepage com- ,pensatingfmeans includingmeans for moving said rollerV carriage on said frame in a directionlongitudinallyv of the blade, and means cooperable with ythe scallops ofthe blade for detecting displacement' ofthe scallops from saidpredetermined 'position `with relation to said grin-ding `means (and toeilect movement of said roller carriage in'a direction to correct su-chdetected displacement. i

l1. In a machine for grinding a scalloped, beveled cutting edge on ablade, the combination of a frame. a blade feeding roller adapted forfrictional driving engagement with the blade to be ground, a roller forsupporting the blade in frictional driving contact with said feedingroller, means for tensioning a length of the blade adjacent to saidfeeding roller, a carriage'for said rollers'mounted on said frame formovement longitudinally of the blade, said rollers beingrotatablesontheir axes on said carriage, means forintermittentlyrotating said feeding roller through an' angle such asvvillV feed the blade ahead a 'distance substantially equal to thedistance between blade crests, a'grindingv means mounted on said frame'andoperable to grind a `scallop of the tensioned length of the Vbladewhen the blade is positioned with its scallops ina predeterminedlongitudinal position with relation to said grinding means, bladecreepa'ge compensating means including a feeler member engageable withthe blade 'edge on opposite' sides of successive crests Ybetweenscallops at times between times of feeding of the blade for 'detectingdisplacement of the scallops from said predetermined position'withrelation' to said grinding means, and means controlled by said feelermember Afor moving said roller carriage in a direction to compensate thedisplacement so detected.

. Y 12,-In a machine for grinding' a scalloped, beveled cutting edge ona blade, 'the combina- ,tion Yofa frame. a blade feeding roller adaptedvfor-frictional drivingengagement with the blade to be ground, arollerfor supporting the blade yin frictional driving contact with saidfeeding roller, means for tensioning a length of the blade adjacent tosaid feeding roller, a carriage for said rollers mounted on said framefor movement longitudinally. of the blade, said rollers beingrotatableon their axes on said carriage, means forintermittently?rotating fsaid' feeding roller ,through an angle such;aswll feed the Ablade raheada distance substantially equal tothedistance between jblade crests, 'a grindingmeans mountedv on saidframe and operable to grinda scallop ofthe tensioned' length of theblade when .thei blade is positioned with ,its scallops in apredetermined flongitudinal `position with relation tosaid grindingmeans, blade creepage compensating.y means including "electricallypowered means for moving said roller vcarriage in either directionlongitudinally 'of the blade', and means cooperable -with the scallopsofthe blade between times of feeding of the blade and includingelectrical energizing circuiting for said electrically powered meanslfor detecting displacements in either direction ofthe Ascallops 4fromsaid predetermined position and for energizing said electrically poweredmeans to move'the'roller carriage in a direction to compensatedisplacements detected. C

' 13. In a machine 'for 'grinding' a scalloped,

vbeveled cutting ledge on a) blade, the combination `of a frame, a bladefeeding roller adapted for frictional drivingengagement with the bladeto be ground, a roller forsupporting'the blade in frictional .drivingcontact 4with said feeding roller, means for tensioning alengtli of theblade ad- 'jacent to said feeding roller, a carriage for said rollersImounted-on said-frame for movement longitudinally of theV blade, saidrollers being rotatable von their axes on said carriage, means forintermittentlyv rotating said feeding roller through an Vangle such aswill feedthe blade ahead.' a distance substantially equal to thedistance between bladecrests, a grinding means mounted on said framefand operable to grind a scallop of the tensioned length of thebladewhen 'the 'blade is, positioned with its scallops in apredetermined longitudinal position with relation to said grindingmeans,V blade creepage compensating means including'` electricallypowered means for moving saidV roller carriage in either directionlongitudinally of the blade, separate electrical'circuitsadaptedtobeswitched to cause operation of said electrically powered means to movesaid roller carriage' in opposite directions, and 'means cooperable withthe scallops of the blade between times of feeding of the blade fordetecting displacements in either direction of the scallops from saidpredetermined position and for switching said electrical circuits tocause operation of said electrically powered meansgto move said rollercarriage in a direction to compensate the displacement. detected. Y f

14`1'n a machine for grinding a scalloped, beveled cutting edgeon ablade, the combination of arframer,v a blade feeding roller adapted forfrictional Ydriving engagement with the blade to be ground, a roller forsupporting the blade in frictional driving contact with said feedingroller, means for tensioning 'a length of the blade adjacent to saidfeeding roller, a carriage forA said rollers mounted on said frame formovement longitudinally of the blade, said rollers being rotatable ontheir axes on said carriage, means for intermittently rotating saidfeeding roller through an angle such yas will feed Vthe blade ahead adistance substantially equal to the distance between blade crests, agrinding means mounted on said frame and operable to grind a scallop ofthe tensioned length of the blade when the blade is-positioned with itsscallops in a predetermined longitudinal position with relation to' saidgrinding'mea'n's, blade creepage compensating means includingelectricallyv powrf4 .ered means for moving saidy roller carriage ineither direction longitudinally of the blade, separate normally openelectrical circuits adapted when energized to effect operation of saidelectrically powered means to move said roller carriage in oppositedirections, and means cooperable with the scallops of the blade betweentimes of feeding of the blade for closing one or the other of saidcircuits as the scallops of the blade become displaced in one directionor the other from said predetermined position in such aman. ner thatsaid electrically powered means is operated to move said roller carriagein a direction to correct such displacements of the blade.

15. In a machine for grinding a scalloped, beveled cutting edge on ablade, the combination of a frame, a blade feeding roller adapted forfrictional driving engagement with the. blade to be ground, a roller forSupporting the blade in frictional driving contact with saidfeedingroller, means for tensioning a length of the blade advjacent tosaid feeding roller, a carriage for said rollers mounted on said framefor movement longitudinally of the blade, said rollers being rotatableon their axes on said carriage, means for intermittently rotatingsaidfeeding roller through an angle such as will feed the blade Aahead adistance substantially equal to the distance between blade crests, agrinding means mounted on said frame and operable to grind a scallop ofthe tensioned length of the blade when the blade is positioned with itsscallops in a predetermined longitudinal position with relation to saidgrinding means, blade creepage compensating means including a feelermember intermittently engageable with the vscalloped blade edge,at-times while the blade feeding roller is stationary, saidfeeler'member beingA movable by the blade edge in accordance withdisplacement ofthe scallops of the blade from said predeterminedposition, velectrically powered means for moving said roller carriage inreverse directions, and electrical circuiting for energizing saidelectrically powered means controlled bymovement of said feeler memberby its engagement with the scalloped blade edge.

16. In a machine for grinding a scalloped, beveled cutting edge on ablade, the combination of a frame, a blade feeding roller adapted forfrictional driving engagement with the blade to be ground, a roller forsupporting the blade in frictional driving contact with said feedingroller, means for tensioning a length of the bladeadjacent to saidfeeding roller, a carriage for said rollers mounted on said frame formovement longitudinally of the blade, said rollers being rotatable ontheir axes on said carriage, means for intermittently rotating saidfeeding roller through an angle such as will feed the blade ahead adistance substantially equal to the distance between blade crests, agrinding means mounted on said frame and operable to grind a scallop ofthe tensioned length of the blade whenl the blade is positioned with itsscallops in a predetermined longitudinal position with relation to saidgrinding means, blade creepage compensating means including a pivotedsaddle member intermittently engageable with the blade edge on oppositesides of successive crests between scallops at times while the bladefeeding roller is stationary, said saddle member being movable on itspvot axis in opposite directionsv as it engages.l the blade edge inaccordance with displacement of the blade scallops in one direction orthe other 'l5 from said predetermined position, electrically poweredmeansfor moving; saidJ roller carriage in reverse directions, andelectrical circuiting .for energizing said electrically powered means:controlled by said pivotal movement of said saddle element.

17. In a machine for grinding a scalloped, beveled cutting edge on ablade, the combination of a frame, a blade feeding roller adapted forfrictional driving engagement with the blade; to be ground, a roller forsupporting'v the blade; in frictional drivingcontact with said feedingroller, means for tensioning a length of the blade ade jacent tosaidfeeding roller, a carriage for said rollers mounted on said framefor movement longitudinally of the blade, said rollers being rotatable,`on their axes on said vcarriage'pa/wl and ratchet means forintermittently rotating said. feeding roller through an angle suchasrwill feed the blade ahead a distance substantially equal to thedistance between blade crests, a grinding meansy mounted on. said frameland be ground, means for supporting the blade in frictional drivingcontact with said feeding roller, meansy for tensioning a length of thebladey adjacent to said` feeding roller, a carriage; for said rollermounted on said frame Yfor movement-longitudinally of the blade, `saidroller beingrotatable on its axis on said carriage, means forintermittently rotating said feeding roller through an angle such aswill feed the blade ahead a distance substantially equal to the distancebetween blade crests, a grinding means mounted on said frame andoperable to grind a scallop of the tensioned length of the blade whenthe blade'is positioned with its scallops in a predeterminedlongitudinal lposition Vwith relation to saidgrinding means,

blade creepage compensating means including, a lead screw for drivingsaid roller carriage,I elec,- trically powered means for rotatingsaidlead screw inV reverse directions, and means cooperable.

with the scallops of the blade. between times of feeding of the bladevand including electrical energizing circuitingfor said electricallypowered means for detecting displacements in eitherdirection of thescallops from said predetermined position and for energizing saidelectrically powered means to rotate said leadv screw in a direction tocompensate the displacement detected.

19. In a machine for grinding a scalloped, beveled cutting edge on ablade, the combinationA of a frame, frictional blade feeding meanssupported by said frame and adapted for frictional drivingengagementwith the blade, means on. said frame for intermittently operating saidblade feeding means to advance the blade through a distance equalsubstantially to the distance between crests of the scalloped blade, agrinding means mounted on said frame and operable to grind a scallop ofthe blade wlfien'thev bladeV 'is positioned with its scallops inv apredetermined 'lngitudinal position withy relation to said grind- .L.20. In a machine for grinding a scalloped, beveled cutting edge on ablade, the combination of a frame, frictional blade feeding meanssupport- Yed by said frame and adapted vfor frictional drivingengagement with the blade, means on said frame for intermittentlyoperating said blade feedingmeans to advance the blade through a'distance equal substantially to the distance between crests of thescalloped bladetensioning means frictionally engageable with the bladefor tensioning aV length of the blade between said tensioning Ameans andthe said blade feeding means, a grinding means mounted on said frame andoperable to grind a scallop of the blade within said tensioned sectionof the blade when the blade is positioned with its scallops in apredetermined longitudinall position with relation to said grindingmeans, adjustment means for 'ei'ecting relative movement along adirection line longitudinally of the blade between the blade and thegrinding means, and means cooperable with the scallops of the blade fordetecting displacement of the scallops from said predetermined positionwith relation to the grinding means and for causing operation of saidadjustment means ina manner to correct the detected displacement.

21. In a machine for grinding a scalloped, bev,- eled cutting edge on'ablade, the combination of a frame, a blade feeding roller adapted forfrictional driving engagement with the blade to be ground,'means forsupporting the blade in fric- -tional driving contact withsaid roller,means for tensioning a length of the blade adjacent to saidfeedingrollenf roller supporting means on said Vframe suppbrting saidroller for rotation on its axis?.v and for bodily movement with relationto said frame in a direction longitudinally of the blade, means for',intermittently rotating said feeding rollerl through an angle such aswill feed the blade ahead a'distance substantially equal to the distancebetween blade crests, a grinding means mounted on said frame andoperable to grind a scallop of the tensioned length of the blade whenthe blade is positioned with its scallops in a predeterminedlongitudinal position with relation to said grinding means, bladecreepage compensating means for bodily moving said roller in freversedirections longitudinally of the blade in a manner to adjust thelongitudinal position of the blade with relation to said grinding means,and means cooperable with the scallops of the ,blade for detectingdisplacement ofv the scallops from said predetermined position withrelation to the grinding means and for causing operation of saidcompensating means in a direction to correct the detected displacement.

` 22. In a machine for grinding a scalloped, bev'- eled cutting edge ona blade, the combination of a frame, frictional blade feeding meanssupported by said frame and adapted for frictional driving engagementwith the blade, means on said frame for intermittently operating saidblade feeding means to advance the blade through a distance equalsubstantially to the distance between crests of the'scalloped blade,'agrinding means mounted on said frame 'and operableto grind a scallop oithe blade when'the blade is vpositioned with its scallops in apredetermined longitudinal position with relationfto said grindingmeans, adjustment means for eiecting rela- -tive movement along adirection line longitudinally of the blade betweenthe blade andthegrinding means, Va feeler member Aen gageable with the blade edge onopposite sides of successive crests between times of yfeeding of theblade,

ysaid feeler member being adapted toassume different positions by virtueof its engagement with the blade edge' depending upon the degree anddirection of displacement of the blade scallops from said predeterminedposition, and' means controlled by the positioningof said feeler memberby the blade edge for causing operationof Vsaid adjustment means in a`manner to correct displacement of 'thescallops fromv said predeter-.mined position. Y

23. In a machine for grinding a scalloped, bevL eled cutting edge on ablade, the combination of a frame,' irictional blade feeding meanssupported by said frame and adapted for frictional driving engagementwith the' blade,`means on said frame for-intermittently operating saidblade feedingmeans to advance the blade through a distance equalsubstantially to the distance be` tween crests of the scalloped blade, a-grinding meanslmounted on* said'frame and operable to grind ascallop ofthelbladewhen the blade'isk positioned with its scallbpsiin lapredetermined;

longitudinal position withfrelation to said grinding means, adjustmentmeans for efiecting rela- 'tive movement along a directionlinelongitudivnally of' the blade between the blade and the grinding means,a pivoted saddle member intermittently engageable with the blade edge onopposite sides ofsuccessive crests between scallops at times while theblade feeding roller is Vvstationary, said saddle member lbeing movableon its pivot axis in opposite directions as it engages the blade edge inaccordance with displacement of the' blade scallops 'in one direction orthe other from said predetermined position,

and means controlled by pivotal movement of said saddle member foroperatingfsaid adjustment means in one direction or'the other 4inaccordance with the direction ofv pivotal movement oi said saddlemember, all in such manner as to` correct vdisplacements'in eitlqierIdirection of said blade scallops from said predetermined position. f A Y24.' In a machine for grinding a scalloped,"beveled cutting edge'on ablade,lthe combination of means f or supporting said blade forlongitudinal travel, means for intermittentlyadvancing said'blade adistance equal to the distance be- `by the deiiection of said feelermember by the blade edge for longitudinally moving the blade to bringits scallops into register with said predetermined position.

WILLIAM WALTER HARTMAN.

